The inventive concepts relate to semiconductor memory devices and methods of fabricating the same. More particularly, the inventive concepts relate to three-dimensional (3D) semiconductor memory devices and methods of fabricating the same.
Semiconductor devices are becoming more highly integrated to provide high performance and low costs. The integration density of semiconductor memory devices directly affects the costs of the semiconductor memory devices, thereby resulting in demand for highly integrated semiconductor devices. An integration degree of a conventional two-dimensional (2D) or planar memory device is mainly determined by an area that a unit memory cell occupies. Therefore, the integration density of a conventional 2D memory device may be greatly affected by a technique of forming fine patterns. However, because extremely high-priced apparatuses are needed to form fine patterns, the integration density of 2D memory devices continues to increase but is still limited. Thus, research has been conducted for a 3D semiconductor memory device including memory cells that are vertically arranged.